The capacity and performance of portable personal computers (PPCs), such as laptop computers, notebook computers and the like, have been enhanced to such an extent that thermal dissipation requirements have increased dramatically. Since the beginning of 1996, thermal dissipation requirements of portable personal computers (PPCs) have increased from about 10 Watts to 20 Watts and continue to increase. The increase in thermal dissipation results from increasing CPU performance and additional functionality, such as digital video disk (DVD), modem, audio, video and the like.
As elucidated in an article by Albert Yu, "The Future of Microprocessors", IEEE Micro, December, 1996, pages 46 through 53, the trend of increasing power dissipation in PPCs will continue for the foreseeable future. For instance, the cooling limit for a PPC employing a typical A4 form factor (210 mm width by 297 mm length), without a fan, is currently approximately 15 to 20 watts. Therefore, there is a need to provide improved cooling techniques to meet the anticipated thermal dissipation requirements.
One approach to increasing heat dissipation in a computer is found in U.S. Pat. No. 5,424,913 to Swindler which discloses an access door/heat sink mounted in a portion of a computer housing. Specifically, the access door includes a heat sink having a heat receiving portion positioned to mechanically contact a surface of a heat generating component. The access door further includes a heat dissipating portion forming an outer surface of the access door and capable of dissipating heat received from the component. The heat dissipation technique of the Swindler patent requires the access door to be in contact with the heat generating component. Accordingly, the technique provides limited cooling only to those components in direct contact with the access door and requires the use of thermally transmissible materials.
Another approach is found in U.S. Pat. No. 5,430,609 to Kikinis, which discloses another heat sink arrangement to cool CPUs in portable computers. The Kikinis patent employs a layer of compressible, heat conducting material positioned between the CPU and a heat sink plate. Similar to the Swindler patent, the heat sink plate is part of an access panel of a computer housing. The Kikinis patent requires the CPU to be in thermal contact with the heat sink plate (via heat conducting material and provides cooling only for the CPU.
There is a need to provide a computer arrangement which allows for greater thermal dissipation and cooling of heat generating computer components, without significantly increasing overall size, weight and complexity. There is also a need for a passive cooling arrangement which provides a competitive advantage and a product differentiation from currently available computers.
Accordingly, it is an object of the present invention to provide an arrangement which enhances the heat dissipation of heat producing components in a PPC.
It is a further object of the present invention to increase ambient air flow at and around heat dissipating PPC components.
Another object of the present invention is to increase ambient air flow in a PPC housing without increasing the size and weight of the PPC.
It is also an object of the present invention to provide a latch mechanism for the keyboard and display to prevent a user from interfering with the ambient air flow, during the operation of a PPC.